FIG. 1 depicts a conventional method 10 for forming a read transducer. The conventional method 10 commences after the conventional magnetoresistive stack has been formed. The magnetoresistive stack typically includes a conventional antiferromagnetic (AFM) or pinning layer, a conventional pinned layer, a conventional spacer layer, and a conventional free layer. The magnetoresistive stack is typically formed on other structures, such as, shield(s), and/or write transducer(s). A conventional magnetoresistive sensor is defined in the track width direction from the conventional magnetoresistive stack, via step 12. Step 12 typically includes covering a portion of the magnetoresistive stack with a mask and ion milling the exposed portion of the stack. Thus, the conventional magnetoresistive sensor in a read transducer is defined in the track width direction using step 12. The track width direction is parallel to the air-bearing surface (ABS) and generally perpendicular to the layers of the magnetoresistive stack.
The magnetoresistive sensor is oxidized, typically by direct exposure to an oxidant such as ozone (O3), oxygen, or an oxygen plasma, via step 14. Exposure to the oxidant in step 14 allows formation of an oxide layer on the sides of the conventional magnetoresistive sensor. Typically, this oxide layer is formed to a thickness of greater than ten Angstroms within a few seconds of exposure to ozone. Formation of the oxidation layer is desirable for passivation of the sides of the conventional magnetoresistive sensor. In particular, damage created by the ion mill that defines the magnetoresistive junction may be repaired and redeposition oxidized to prevent shorting.
After oxidation, a conventional insulating layer, such as aluminum oxide, is provided, via step 16. The oxide layer formed in step 14 resides between the aluminum oxide layer and the conventional magnetoresistive sensor. Hard bias structures for biasing the magnetoresistive junction are then provided adjacent to the conventional insulating layer. The hard bias structures are used to magnetically bias the conventional magnetoresistive sensor. Fabrication of the device may then be completed, for example by formation of additional shields, contacts, write transducers, and/or other structure.
FIG. 2 depicts an ABS view of a conventional magnetic read transducer 20 used in reading a media (not shown) and fabricated using the conventional method 10. For clarity, only a portion of the conventional read transducer 20 is shown. Referring to FIGS. 1-2 the conventional read transducer 20 is shown after completion of step 18 of the conventional method 10. The conventional magnetic transducer 20 is formed on substrate 22 and includes conventional magnetoresistive sensor, 30. The substrate 22 may be a shield. The conventional magnetoresistive sensor 30 includes a conventional AFM layer 32, a pinned layer 34, a spacer layer 42, a free layer 44 and a capping layer 46. The pinned layer 34 is a synthetic antiferromagnet including ferromagnetic layers 36 and 40 separated by a thin nonmagnetic spacer layer 38. Typically, the ferromagnetic layers 36 and 40 are antiferromagnetically coupled. The spacer layer 42 may be conductive or an insulating tunneling barrier layer. Also shown are oxide layers 24A and 24B formed by oxidizing the sensor 30, insulating layers 26A and 26B, and hard bias structures 28A and 28B.